Hydraulic pressing units and methods of operating the same are known. In this respect, reference is made for example to DE 198 25 160 A1. Described there is a hand-operated pressing unit which is provided with a return valve that is triggered when a predetermined pressure on the moving part is reached or exceeded. After opening of the return valve, the moving part returns under spring biasing, with the hydraulic medium that acts upon the moving part being forced back into the supply chamber via the return valve. This achieves a pressure acting on the return valve that only corresponds to a fraction of the triggering pressure of the return valve but keeps the return valve in the open position. If the pressure drops below this predetermined return pressure, the return valve closes, after which the pressing unit is ready again for the next pressing operation.
In the case of the known unit, a method of the generic type has already been realized to great advantage and has found widespread use. It is usually also the case that the configuration is advantageous and satisfactory. However, there are situations in which early stopping of the moving part in the return direction is desired, without the displacement of the moving part into the end position being obstructed in other cases.
With regard to the prior art described above, a technical problem for the invention is seen in providing a method of operating a hydraulic pressing unit that makes it possible for the moving part to be stopped in a position according to choice.